Lasing of infrared free-election lasers using the storage ring NIJI-IV

Abstract

We report for the first time to our knowledge the experimental achievement of a storage ring free-electron laser (FEL) device dedicated to applications in the IR region. IR FELs were oscillated in the wavelength region of 1392-1502 nm, and the relative linewidth was 3 x 10(-4). The maximum power of the IR FEL transmitted through a vacuum window was approximately 0.3 mW, and the intracavity power was approximately 2 W. We have already observed an intensive quasi-monochromatic x ray by using FEL Compton backscattering. The results of our study are expected to lead to applications in which an IR FEL and a quasi-monochromatic x ray will be used simultaneously.

Proposal of coherent Cherenkov radiation matched to circular plane wave for intense terahertz light source

“…Because the CCR can be generated by using the hollow conical dielectric with a large inner diameter, the loss of the electron beam is negligible. This intense CCR can be used simultaneously with other light sources based on the electron accelerator, such as an FEL and parametric X-ray radiation [19][20][21]. In this article, we provide a basic theory of the CCR matched to a circular plane wave (CCR-MCP).…”

Electron-bunch lengthening on higher-harmonic oscillations in storage-ring free-electron lasers

“…The electron energy in the infrared FEL experiments operated in single electron-bunch mode was 310 MeV. The relative energy spread of the electron bunch was 4.0 Â 10 À4 in the single-bunch mode, and the bunch length, which was independent of the electron-beam current below 5 mA, was approximately 90 ps (Sei et al, 2009). Dielectric multilayer mirrors having target wavelengths of 870 nm were used in the experiments (Sei et al, 2010).…”

“…The saturated output power was measured using a calibrated power meter (Coherent Inc., OP-2 IR) with the fundamental and the third-harmonic FEL oscillations at a wavelength of $ 1530 nm (Sei et al, 2017). Fig.…”

“…Previously, we have carried out advanced studies to determine the characteristics of higher-harmonic FEL oscillations using the infrared FEL system of the NIJI-IV storage ring (Yamazaki et al, 1998;Sei et al, 2009). We demonstrated the generation of FEL oscillations using up to the seventh harmonic (Sei et al, 2012b), which is the highest harmonic order ever achieved in the field of higher-harmonic FEL oscillations.…”

Inverse Compton scattering of coherent synchrotron radiation in an energy recovery linac

“…Furthermore, a quasimonochromatic x ray is observed in ICS induced by free-electron laser (FEL) [5]. A high-brilliance x-ray photon source based on ICS with a superconducting linac is under development [6].…”